In the 1940's, after WWII, the US Military desired a replacement rifle for the M-1, the Browning Automatic Rifle, the Carbine and the M3 A-1 Sub-machine gun. In many cases a squad would be carrying each of these four weapons in battle. The variety of weapons and ammunition was inefficient and as such, a replacement weapon for all four of the above mentioned weapons was developed. This weapon was the U.S. Rifle M14.
The M-14 uses a standard 7.62 mm×51 NATO round and may be fired semiautomatic (one round fired with each trigger pull), or full automatic (continuous fire as long as the trigger is held in the firing position and there are rounds in the magazine). The M14 has a muzzle velocity of 800 m/s (2800 ft/sec) and provides a high degree of accuracy along with an effective range rating of 800 meters (with optics). The M14 is still used today as a sniper rifle in some military units. The M14 works well in dirty conditions, providing a reliable platform for putting rounds down range with a firing rate of 700-750 rounds per minute. Numerous variations of the M14 have been made including the M39 Enhanced Marksman Rifle (EMR). This is used by a Designated Marksman when precision fire is needed but does not rate a Scout Sniper. In addition, Marine Scout Snipers and Explosive Ordnance Disposal teams use this platform when rapid and accurate fire is needed.
In the 1960's, during the Vietnam conflict, solders complained of the weight of the M-14 in jungle warfare. An M-14 with a loaded 20 round magazine and no optics weighs 11.5 lbs. New on the scene was the M-16, which uses the smaller 5.56 mm×45 NATO round. A M16A1 with a full 30 round magazine weighed in at a mere 7.9 lbs. The slightly modified M16A2 had a firing rate of 700-950 rounds per minute and a muzzle velocity of 950 m/s (3100 ft/sec), both greater than the M14, but the maximum effective range was lower at 550 meters. The smaller 5.56 mm M16 round not only lacked in the range of the M14, but also lacked stopping power compared to the 7.62 mm round of the M14. The M14 has a 22 inch barrel with an overall length of 44 inches. The M16A2 is 39.5 inches long and all M16 variations use a 20 inch barrel. Other variations of the M16, including the M4 Carbine uses a 14.5 inch barrel with an extended stock length of 33 inches. The shorter barrel reduces the maximum effective range but the shorter rifle makes maneuvering the rifle in a shooting position easier when clearing buildings and going through doorways.
In today's urban warfare environments, it may be desirable to combine the reliable and more powerful platform of the M14, but put it in a lighter and more compact tactical weapon platform. This need may be met by the Bullpup. The Bullpup may take the M14's 22 inch barrel, receiver and trigger group and position it in a stock to provide a more compact weapon than the 44 inch traditional M14 rifle. This may be done by locating the proximal end of the barrel behind the trigger group. To accomplish this, the stock and rail assemblies may be replaced and a new trigger assembly added, which actuates the existing M14 trigger assembly. The existing barrel of the M14 is still used. There have been attempts to create Bullpup rifles, which have been met with limited success. A common area of deficiency of existing systems is the interaction between the new trigger and the existing M14 trigger, several inches away. In addition to the coupling of the actuation of the old trigger with the new trigger, there is a need for a reliable safety to prevent actuation of the weapon when set to “safe”. The firing control mechanism as shown and described may provide these features.